The invention relates to retaining elements such as barriers, railings, fences, or the like, and in particular, retaining elements having fasteners including threaded members extending into holes in a supporting undersurface.
In the past, elements such as handrails of the kind having one or more horizontal rails supported by regularly spaced uprights, were often made of pipe-like tubes, held in place by plates welded perpendicular to the lowermost end of the uprights. The plates were anchored using fastening means such as through-bolts, bolts and anchors, or the like. These retaining elements and their fastening means are expensive and are, in addition, difficult and time-consuming to install. Furthermore, these retaining elements, useful to serve a temporary function such as crowd control, are not easily or inexpensively removed and relocated elsewhere.
In addition, the multiple anchoring means used in the past in proximity to one another, such as the two or more bolts placed through each welded plate, tend to concentrate load in the underlying supporting structure by causing overlapping shear cones therein, which increases the probability of cracking.
The heavy bolts and anchors often used for handrails or other barriers intended only to retain personnel, i.e., as on railroad trestles for example, were often unnecessary in view of the relative light loading anticipated.
It is an object of the present invention to overcome the above-described shortcomings of the known retaining elements, while providing several unique improvements which result in reduced costs, ease and flexibility of installation, and ease of removal and relocation.